The invention relates to a support construction for escalators and moving walkways which substantially consists of two wall supports, which are arranged laterally of a step or plate conveying run and oriented predominantly in the longitudinal and vertical directions and which are connected together by crossbeams. The invention has constructional adaptations for use for large support widths.
Escalators or moving walkways, which in free-supporting manners bridge over large distances, require executions of the support constructions which are stiff in bending or torsion in order to avoid disturbing bending or torsional oscillations in operation. Such oscillations can be excited not only by periodic pulses from the drive or the circulating step conveying run, but also by passengers walking along the run. Large bending or torsional oscillations which are disturbing or even risk-laden can be most easily avoided by an execution of the support construction having high rigidity and low mass, which creates correspondingly high natural frequencies.
Conventional support constructions for escalators and moving walkways substantially consist of so-called wall supports which are arranged at both sides of a step or plate conveying run and are connected together by crossbeams and which are predominantly oriented in the longitudinal and vertical directions. These constructions are usually produced in a framework mode of construction from rolled profile members or rectangular tubes, but can also be fabricated in accordance with other methods, such as, for example, in solid wall or in sandwich modes of construction. Standardized wall supports are, for reasons of cost optimization, so designed that the rigidity of the support constructions produced therefrom is for the predominant part sufficient for all bridging distances typically encountered. For the remaining constructional realizations with larger bridging distances, costly special solutions usually have to be used, such as support constructions with wall supports of greater height, support constructions of thicker profile members or support constructions with stiffening supplementary constructions.
A solution is known from EP 0 366 019 Al in which so-called sub-bracing xe2x80x94additional sub-trusses of wire cables or tie rods xe2x80x94produces the required increase in bending stiffness. Unfavorable results of this solution are that the aesthetic appearance of such an escalator can be perceived as unsatisfactory, that the construction demands more installation space in vertical direction, and that special additional components have to be designed and produced for the sub-bracing.
The present invention therefore has the object of achieving an increase in bending and torsional stiffness of a support construction, which is needed for long escalators and moving walkways, at low cost in terms of production and logistics and with the avoidance of the afore-described disadvantages.
According to the invention the foregoing and other objects are met in that at least one respective, usually constructional identical, supplementary wall support is flange-mounted to each of the two basic wall supports of the support construction. In this manner there is created from each single wall support and a supplementary wall support a double wall support which imparts correspondingly increased rigidity to the support construction.
The invention exhibits substantial advantages relative to constructions in which the geometry or the constructional materials of the wall supports are respectively matched to the bridging length or special constructions are implemented. All wall supports can be produced according to the same standardized methods from identical tube materials with the same machine settings and gauge sizes. Tube materials and processing tools are required to be kept in store only for a single constructional execution. For mass production, it is only necessary to stock prefabricated wall supports in one form of construction. Further, the aesthetic appearance of the escalator or moving walkway in which the invention is embodied is not impaired by increased height or by visible additional constructions.
An additional advantage of the described principle of reinforcement is that it is usable for the most diverse kinds of constructional executions of wall supports, including, for example, framework, solid plate, bending profile member and composite panel modes of construction.
In certain circumstances further advantages may result from the use of supplementary wall supports of a type of construction differing from that of the basic wall support, i.e., for example, a supplementary wall support of a solid plate mode of construction being flange-mounted to a basic wall support having a framework mode of construction.
In situations where unforseen disturbing oscillations occur after placing the equipment into operation, such oscillation can be eliminated by subsequent attachment of supplementary wall supports.